Sharpening attachment



Oct. 23, 1962 R. E. WALLIN ETAL 3,059,383

SHARPENING ATTACHMENT Filed March 20, 1961 2 Sheets-Sheet l INV NTORSROBERT E. WALLIN ALLISON W. BLANSHINE BY 4 Q g ATTORNEY Oct. 23, 1962 R.E. WALLIN ETAL SHARPENING ATTACHMENT 2 Sheets-Sheet 2 Filed March 20,1961 INVENTUR ROBERT E. WALUN ALLISON W. 5%NSHINE BY M 9 ,qrr o mvfivUnited States Patent 3,059,383 SHARPENING ATTACHMENT Robert E. Wallin,New Holland, and Allison W. Blanshine, Lititz, Pa., assignors to SperryRand Corporation, New Holland, Pa., a corporation of Delaware Filed Mar.20,1961, Ser. No. 97,009 1 Claim. (Cl. 51246) The present inventionrelates to an improvement in sharpening attachments or devices of thetype shown and described in US. Patent Nos. 2,735,248 and 2,788,623,assigned to the assignee of this invention.

Each of the patents mentioned shows a device having a carriage manuallyreciprocable over a guide track. The track is radially spaced from andextends parallel to the axis of a cylindrical rotatable cutter havingknives which have to be sharpened periodically. The carriage has anadjustable tool holder which supports an abrasive sharpening element. Byadjusting the tool holder to proper position and then reciprocating thecarriage, the abrasive element is engageable with the cutter knives toapply a sharpening or honing action thereon. When the cutter knives aresharpened, they wear away the abrasive element and it is necessary toindex the element toward the cutter to compensate for such wear. In thepatents mentioned, the tool holder is indexed toward the cutter eachtime the carriage is returned to a starting position. The carriage isreciprocated from a starting position at one axial end of the cutter. Itis moved to the opposite axial end of the cutter and then back tostarting position. At the starting position, the holder for the abrasiveelement is indexed to compensate for the wear of the sharpening elementduring the prior reciprocating stroke.

A difliculty with this type of arrangement is that if the carriage isreciprocated at a contsant speed, the portions of the knives at theaxial end of the cutter adjacent the starting position of the carriagereceive most of the sharp ening action, while the portions of the knivesat the other axial end of the cutter get insufficient sharpening. Thisresults from the fact that the sharpening element has its greatestsharpening efiect when it first starts out. As it wears away, thesharpening eflect decreases. While the sharpening variation from one endof the cutter to the other is relatively slight, for a givenreciprocation of the carriage, the result is cumulative. Every time thecutter is sharpened, one axial end thereof is sharpened a little morethan the other end. In time, the trueness of the cylinder generated bythe cutter knives is impaired. This occurs particularly where the cutteris of substantial axial length. The greater the length of the cutter,the greater the sharpening problem. Uneven sharpening reduces operativeefiiciency of the cutter.

Such problem can be minimized if the operator will move the carriagerapidly when passing over the axial portion of the cutter near thestarting position of the carriage and slowly when passing over theopposite end of the cutter. However, such method requires carefulattention of the operator.

A main object of this invention is to provide a sharpening attachment ofthe character described having improved indexing means thereon, forinsuring that the knives of the cutter to be sharpened are honed as muchat one axial end of the cutter as at the other end.

Another object of this invention is to provide a sharpening attachmentof the character described wherein improved indexing means operates withprecision and costs very little over the structure heretofore provided.

Other objects of this invention will be apparent hereinafter from thespecification and from the recital in the appended claim.

In the drawings:

FIG. 1 is a longitudinal vertical section through a 3,059,383 PatentedOct. 23, 1962 cutter mechanism having mounted thereon a sharpeningattachment constructed according to this invention, such section beingtaken on the line 1-1 of FIG. 2 looking in the direction of the arrows;and

FIG. 2 is a plan view of FIG. 1.

Referring now to the drawings by numerals of reference, 10 denotes aforage harvester housing having a forward inlet opening 11 and arearward outlet open ing 12. Housing 10 has a pair of laterally spacedside walls 14 and 15, and a top wall 16 having an opening 18. Rotatablein the housing 10 in the direction indicated by the arrow 19 is a cutter20. The cutter 20 has a shaft S of substantial axial length driven froma source of power, not shown. Shaft S supports three radially outwardlyextending support discs 21 axially spaced along shaft S. Discs 21 carrysupport castings 292 for cutter knives 24. Each of the knives 24 has acutting edge 25, all of the knife edges being located at the same radialdistance from shaft S and which on rotation of the cutter generate acylinder.

As shown best in FIG. 1, the knives 24 are cupshaped. They are operativeto exert a throwing as Well as a cutting effect on forage fed throughopening 11. The cut or chopped material is discharged through the outlet12 and through a spout 26. Spout 26 terminates at a container, notshown, which receives the material. In front of the inlet 1 a pair offeed rolls 2S and 29 are provided between which the forage to be choppedpasses. Such forage may comprise hay, corn or other crop material. Therolls 2-8 and 29 opcrate to compress the crop material as well as feedit into the housing 10. The material passes over infeed plate 30adjacent the lower portion of the opening 1 1. A fixed shear bar 31 ismounted adjacent the opening 11 and cooperative with the knives 24 onthe cutter. As the cutter 20 operates, the knives 24 successively passthe shear bar 31 and sever the material being fed thereover. The knivesextend angularly (FIG. 2) relative to the axis of shaft S, whereby theyexert a shearing action as they pass the shear bar 31. The cut cropmaterial is swept along the lower arcuate portion 32 of the housing 10by the knives 24 and then thrown upwardly through the discharge opening12 and spout 26. As will be noted, the portion 32 of the hous ing isconcentric with the axis of the shaft S. Cutter 20, housing 10 and theinfeed rollers 28 and 29 are all supported on a common frameworkincluding support pipe 34.

In the course of operation of the cutting mechanism, the cutting knives24 become worn. Periodically, the knives must be sharpened to maintain agood cutting and throwing action with a minimum of power. To sharpenknives 24, a sharpening attachment or device 40 is provided which ismounted on top wall 16 and operates through the opening 18. Device 40comprises a guide track 41 having a pair of relatively spaced trackmembers 42 and 44 which extend parallel to each other and parallel tothe axis of cutter 20. Mounted on track 41 for reciprocable movementthereover, is a carriage 45 having members 46 which engage and slide onthe track members 42 and 44. Connected to carriage 41 is a handle 48(FIG. 2) to facilitate manual reciprocation of the carriage over thetrack.

Carriage 45 has a tool holder 50 threaded therein for adjustment aboutan axis transverse to the axis of the cutter 20 whereby the tool holdercan be threaded toward the cutter. Tool holder 5i threadably supports achuck member 51 in which an abrasive sharpening element 52 is mounted.The lower end 53 of the sharpening element projects through the opening18 and is engageable with the cutting edges 25 of the knives 24. Cutter24) rotates at a high rpm. and when the carriage 45 is reciprocated fromone axial end of the track 41 to the opposite end thereof the sharpeningelement 52 moves across the cutting edges of all of the knives on thecutter to thereby sharpen them. When a sharpening action takes place,the lower end 53 of the sharpening element becomes worn and tocompensate for such wear, the tool holder 59 is supported on thecarriage 45 to be indexed downwardly relative thereto by means whichwill now be described.

As shown best in FIG. 2, when carriage 45 is in a retracted startingposition, the sharpening element 52 is disposed at one axial end of thecutter The upper end of the tool holder 50 has radially extendingratchet teeth 54 which'form a ratchet wheel concentric With the axis ofthe tool holder and the sharpening element 52. Teeth 54 are engageablewith a fixed pawl or detent 55 and a resilient holding pawl or detent56. When the ratchet teeth 54 are brought into engagernent with pawl 55,the tool holder 50 is rotated in the carriage 45 and the sharpeningelement 52 is indexed downwardly. Detent 56 provides means to preventretrogressive rotation of the tool. The pawl 55 is fixedly disposed atone end of the guide track 41 and adjacent the track member 44. At theopposite end of the track 41, and thus the opposite axial end of thecutter 20, a pawl 58 is provided which is located adjacent the trackmember 42.. At the outer end of a reciprocating stroke, the pawl 58engages the ratchet teeth 54 and rotates the tool holder 50. A holdingdetent 59 is provided, the same as detent 56, to prevent the tool holderfrom reverse rotating.

Thus, the tool holder is adapted to be indexed downwardly at both endsof a reciprocating stroke. The axial half of the cutter 20 which islocated adjacent the end of track 41 having the pawl 55, is sharpenedprimarily by engagement of the tool holder with the pawl 55. The otheraxial half of the cutter 20 is sharpened primarily by the downwardindexing of the tool holder provided by the fixed pawl 58. Pawl 55 is solocated and of such extent that tool holder 50 is rotated a distance ofone ratchet tooth each time it engages the pawl when carria-ge 45 isretracted. Powl 58 operates in the same manner to rotate the tool holdera distance of one ratchet tooth each time carriage 45 is extended. Thuscutter 20 is uniformly sharpened for its full axial length when carriage45 is reciprocated. No oversharpening of one end of the cutter willresult as happened heretofore, and no special handling of the sharpeneris required by the operator.

While this invention has been described in connection with a particularembodiment thereof, it will be understood that it is capable of furthermodification, and this application is intended to cover any variations,uses, or adaptations following, in general, the principles of theinvention and including such departures from the present disclosure ascome within known or customary practice in the art to which theinvention pertains, and as fall within the scope of the invention or thelimits of the appended claim.

Having thus described our invention, what we claim is:

A device for sharpening a rotatable cutter of substantial axial lengthwhile it is rotating wherein the cutter has angularly spaced kniveswhich on rotation of the cutter generate a cylinder, comprising a guidetrack, said guide track having first and second spaced track membersextending parallel to each other and to the axis of said cutter, acarriage mounted on said track and reciprocable from one end to anopposite end thereof, said carriage when reciprocat'ed traversing thefull axial length of said cutter, a tool holder threadably supported onsaid carriage for adjustment between said track members and toward saidcutter about an axis transverse to the direction of movement of saidcarriage, an abrasive sharpening element carried on said tool holder andengageable with said knives, a ratchet wheel fixedly mounted on saidtool holder and coaxial therewith, said ratchet wheel having a pluralityof ratchet teeth, a first pawl mounted adjacent said first track memberand at said one end of said track, a second pawl mounted adjacent saidsecond track member at said opposite end of said track, said ratchetwheel being engageable with said first pawl when retracted to said oneend of said track and with said second pawl when moved to said other endof said track, said tool holder being rotated to index said sharpeningelement toward said cutter head responsive to each engagement of saidratchet wheel with said pawls, said pawls both operating to rotate saidtool holder in the same direction and being similarly constructedwhereby the amount of indexing of said sharpening element is the same ateach end of said track.

West Feb. 21, 1956 Proctor Apr. 16, 1957

